#include <stdio.h> #include <sys/types.h> #include <unistd.h> #include <stdlib.h> #include <signal.h>
void execute(char **, int, char **); void handle_signal(int); int parse(char *, char **, char **, int *); void chop(char *);
#define INPUT_STRING_SIZE 80
#define NORMAL 00 #define OUTPUT_REDIRECTION 11 #define INPUT_REDIRECTION 22 #define PIPELINE 33 #define BACKGROUND 44 #define OUTPUT_APP 55
typedef void (*sighandler_t)(int);
int main(int argc, char *argv[]) { int i, mode = NORMAL, cmdArgc; size_t len = INPUT_STRING_SIZE; char *cpt, *inputString, *cmdArgv[INPUT_STRING_SIZE], supplement = NULL; inputString = (char)malloc(sizeof(char)*INPUT_STRING_SIZE); char curDir[100]; while(1) { mode = NORMAL; getcwd(curDir, 100); printf("myshell$"); getline( &inputString, &len, stdin); if(strcmp(inputString, "exit\n")== 0) exit(0); cmdArgc = parse(inputString, cmdArgv, &supplement, &mode); if(strcmp(*cmdArgv, "cd") == 0)
chdir(cmdArgv[1]);
else
execute(cmdArgv, mode, &supplement);
}
return 0;#include <stdio.h>
#include <sys/types.h> #include <unistd.h> #include <stdlib.h> #include <signal.h>
void execute(char **, int, char **); void handle_signal(int); int parse(char *, char **, char **, int *); void chop(char *);
#define INPUT_STRING_SIZE 80
#define NORMAL 00 #define OUTPUT_REDIRECTION 11 #define INPUT_REDIRECTION 22 #define PIPELINE 33 #define BACKGROUND 44 #define OUTPUT_APP 55
typedef void (*sighandler_t)(int);
int main(int argc, char *argv[]) { int i, mode = NORMAL, cmdArgc; size_t len = INPUT_STRING_SIZE; char *cpt, *inputString, *cmdArgv[INPUT_STRING_SIZE], supplement = NULL; inputString = (char)malloc(sizeof(char)*INPUT_STRING_SIZE); char curDir[100]; while(1) { mode = NORMAL; getcwd(curDir, 100); printf("myshell$"); getline( &inputString, &len, stdin); if(strcmp(inputString, "exit\n")== 0) exit(0); cmdArgc = parse(inputString, cmdArgv, &supplement, &mode); if(strcmp(*cmdArgv, "cd") == 0)
chdir(cmdArgv[1]);
else
execute(cmdArgv, mode, &supplement);
}
return 0;
}
int parse(char *inputString, char *cmdArgv[], char **supplementPtr, int *modePtr) { int cmdArgc = 0, terminate = 0; char *srcPtr = inputString; //printf("parse fun%sends", inputString); while(*srcPtr != '\0' && terminate == 0) { *cmdArgv = srcPtr; cmdArgc++; //printf("parse fun2%sends", *cmdArgv); while(*srcPtr != ' ' && *srcPtr != '\t' && *srcPtr != '\0' && *srcPtr != '\n' && terminate == 0) { switch(*srcPtr) { case '&': *modePtr = BACKGROUND; break; case '>': *modePtr = OUTPUT_REDIRECTION; *cmdArgv = '\0'; srcPtr++; if(*srcPtr == '>') { *modePtr = OUTPUT_APP; srcPtr++; } while(*srcPtr == ' ' || *srcPtr == '\t') srcPtr++; *supplementPtr = srcPtr; chop(*supplementPtr); terminate = 1; break; case '<': *modePtr = INPUT_REDIRECTION; *cmdArgv = '\0'; srcPtr++; while(*srcPtr == ' ' || *srcPtr == '\t') srcPtr++; *supplementPtr = srcPtr; chop(*supplementPtr); terminate = 1; break; case '|': *modePtr = PIPELINE; *cmdArgv = '\0'; srcPtr++; while(*srcPtr == ' ' || *srcPtr == '\t') srcPtr++; *supplementPtr = srcPtr; //chop(*supplementPtr); terminate = 1; break; } srcPtr++; } while((*srcPtr == ' ' || *srcPtr == '\t' || *srcPtr == '\n') && terminate == 0) { *srcPtr = '\0'; srcPtr++; } cmdArgv++; } /*srcPtr++; srcPtr = '\0'; destPtr--;/ *cmdArgv = '\0'; return cmdArgc; }
void chop(char *srcPtr) { while(*srcPtr != ' ' && *srcPtr != '\t' && *srcPtr != '\n')
srcPtr++;
*srcPtr = '\0';
}
void execute(char **cmdArgv, int mode, char **supplementPtr) { pid_t pid, pid2; FILE *fp; int mode2 = NORMAL, cmdArgc, status1, status2; char *cmdArgv2[INPUT_STRING_SIZE], *supplement2 = NULL; int myPipe[2]; if(mode == PIPELINE) { if(pipe(myPipe)) //create pipe { fprintf(stderr, "Pipe failed!"); exit(-1); } parse(*supplementPtr, cmdArgv2, &supplement2, &mode2); } pid = fork(); if( pid < 0) { printf("Error occured"); exit(-1); } else if(pid == 0) { switch(mode) { case OUTPUT_REDIRECTION: fp = fopen(*supplementPtr, "w+"); dup2(fileno(fp), 1); break; case OUTPUT_APP: fp = fopen(*supplementPtr, "a"); dup2(fileno(fp), 1); break; case INPUT_REDIRECTION: fp = fopen(*supplementPtr, "r"); dup2(fileno(fp), 0); break; case PIPELINE: close(myPipe[0]); //close input of pipe dup2(myPipe[1], fileno(stdout)); close(myPipe[1]); break; } execvp(*cmdArgv, cmdArgv); } else { if(mode == BACKGROUND); else if(mode == PIPELINE) { waitpid(pid, &status1, 0); //wait for process 1 to finish pid2 = fork(); if(pid2 < 0) { printf("error in forking"); exit(-1); } else if(pid2 == 0) { close(myPipe[1]); //close output to pipe dup2(myPipe[0], fileno(stdin)); close(myPipe[0]); execvp(*cmdArgv2, cmdArgv2); } else {
close(myPipe[0]);
close(myPipe[1]);
}
}
else
waitpid(pid, &status1, 0);
}
} }
int parse(char *inputString, char *cmdArgv[], char **supplementPtr, int *modePtr) { int cmdArgc = 0, terminate = 0; char *srcPtr = inputString; //printf("parse fun%sends", inputString); while(*srcPtr != '\0' && terminate == 0) { *cmdArgv = srcPtr; cmdArgc++; //printf("parse fun2%sends", *cmdArgv); while(*srcPtr != ' ' && *srcPtr != '\t' && *srcPtr != '\0' && *srcPtr != '\n' && terminate == 0) { switch(*srcPtr) { case '&': *modePtr = BACKGROUND; break; case '>': *modePtr = OUTPUT_REDIRECTION; *cmdArgv = '\0'; srcPtr++; if(*srcPtr == '>') { *modePtr = OUTPUT_APP; srcPtr++; } while(*srcPtr == ' ' || *srcPtr == '\t') srcPtr++; *supplementPtr = srcPtr; chop(*supplementPtr); terminate = 1; break; case '<': *modePtr = INPUT_REDIRECTION; *cmdArgv = '\0'; srcPtr++; while(*srcPtr == ' ' || *srcPtr == '\t') srcPtr++; *supplementPtr = srcPtr; chop(*supplementPtr); terminate = 1; break; case '|': *modePtr = PIPELINE; *cmdArgv = '\0'; srcPtr++; while(*srcPtr == ' ' || *srcPtr == '\t') srcPtr++; *supplementPtr = srcPtr; //chop(*supplementPtr); terminate = 1; break; } srcPtr++; } while((*srcPtr == ' ' || *srcPtr == '\t' || *srcPtr == '\n') && terminate == 0) { *srcPtr = '\0'; srcPtr++; } cmdArgv++; } /*srcPtr++; srcPtr = '\0'; destPtr--;/ *cmdArgv = '\0'; return cmdArgc; }
void chop(char *srcPtr) { while(*srcPtr != ' ' && *srcPtr != '\t' && *srcPtr != '\n')
srcPtr++;
*srcPtr = '\0';
}
void execute(char **cmdArgv, int mode, char **supplementPtr) { pid_t pid, pid2; FILE *fp; int mode2 = NORMAL, cmdArgc, status1, status2; char *cmdArgv2[INPUT_STRING_SIZE], *supplement2 = NULL; int myPipe[2]; if(mode == PIPELINE) { if(pipe(myPipe)) //create pipe { fprintf(stderr, "Pipe failed!"); exit(-1); } parse(*supplementPtr, cmdArgv2, &supplement2, &mode2); } pid = fork(); if( pid < 0) { printf("Error occured"); exit(-1); } else if(pid == 0) { switch(mode) { case OUTPUT_REDIRECTION: fp = fopen(*supplementPtr, "w+"); dup2(fileno(fp), 1); break; case OUTPUT_APP: fp = fopen(*supplementPtr, "a"); dup2(fileno(fp), 1); break; case INPUT_REDIRECTION: fp = fopen(*supplementPtr, "r"); dup2(fileno(fp), 0); break; case PIPELINE: close(myPipe[0]); //close input of pipe dup2(myPipe[1], fileno(stdout)); close(myPipe[1]); break; } execvp(*cmdArgv, cmdArgv); } else { if(mode == BACKGROUND); else if(mode == PIPELINE) { waitpid(pid, &status1, 0); //wait for process 1 to finish pid2 = fork(); if(pid2 < 0) { printf("error in forking"); exit(-1); } else if(pid2 == 0) { close(myPipe[1]); //close output to pipe dup2(myPipe[0], fileno(stdin)); close(myPipe[0]); execvp(*cmdArgv2, cmdArgv2); } else {
close(myPipe[0]);
close(myPipe[1]);
}
}
else
waitpid(pid, &status1, 0);
}
}